1. Field of the Invention
The present invention relates to a technique of controlling an access to an electronic file.
2. Description of the Related Art
A file storage provided in a network is frequently used to facilitate storage of an electronic file. Ordinarily, multiple users are registered in the file storage. Each user accesses the file storage using a dedicated ID and a dedicated password and stores or acquires a file. Folders called a “personal folder” and allocated to each user are frequently stored in the file storage. Only the user to whom each personal folder is allocated can access the personal folder.
FIG. 1 illustrates a directory structure of the file storage and an exemplary access. In the example illustrated in FIG. 1, users “User A”, “User B”, and “User C” are registered in the file storage, and the folders (the personal folders) of “User A”, “User B”, and “User C” are allocated to the corresponding users, who have authority of solely accessing the corresponding personal folder. According to the authority illustrated in FIG. 1, although the user “User A” can access “file a”, “file y”, and so on, the user “User A” cannot access “file 1” in a folder “User B” and “file i” in a folder “User C”.
In such a file storage, a folder for sharing a file with users is frequently prepared. Referring to FIG. 1, the folder for sharing the file with the users is indicated by “Share”. All users “User A”, “User B”, and “User C” who can access the file storage can access this folder “Share” (a shared folder).
In a case where the file stored in the personal folder is shared in the file storage, the file can be accessed by another user after copying or moving the file to the folder “Share”.
Meanwhile, by giving exceptional authority to the file stored in the personal folder without using the folder “Share”, it is possible for another user to access this file stored in the personal folder.
In the above method of sharing the file using the file storage, since a user operation such as copying/moving of the file or giving of the exceptional authority is necessary, the method of sharing the file is complicated.
Further, in a case where the file in the personal folder is copied or moved to the shared folder, there are problems that all users who can access the file storage can view the file, that a detailed setup of the authority cannot be performed, and that it is not possible to limit the access only to the specific user.
Patent Document 1 discloses a technique of sharing an engineering drawing, a progress of a process, or the like using a chat through a network for the purpose of effectively performing a collaboration among development actors in a product development. However, this technique cannot solve the above problem that the detailed setup of the authority cannot be easily performed.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2005-258937